Numerous studies have been conducted regarding the effect of sport massages on athletes. A majority of these studies have yielded mixed results. One study that compared professional athletes with control subjects found that there were no differences in the amount of muscle soreness. Another study comparing professional athletes and controls revealed a significant improvement in muscle soreness for those who were massaged, but there was no significant improvement for athletes who didn't receive massage. Similar results were also observed in a separate study that contrasted active athletes with non-athletes. Although there aren't conclusive studies proving that sports massage improves athletic performance however, numerous studies have demonstrated that it can aid athletes in recovering faster. Researchers found that athletes who had been engaged in high-intensity training had a lower chance of recovering from sports massage. Another study showed that athletes who were subject to a maximum workload protocol did significantly better than those who were given a Sports massage. In a separate study, therapists who performed sports massage were able to show a marked improvement in the physical performance of overweight adolescents. A study that compared the production of lactic acids in injured and control groups found no difference. Researchers concluded that the effects of massage depend on the person that it is being administered to. Researchers found that lactic acids were produced at a higher rate in the group that was not being massaged than during exercise, and remained quite low after the session. On the other hand, the production of lactic acids was found to be higher in injured group during exercise, and was higher after the session. This could be due to increased production of lactic acid in injured patients may reduce the patient's pain threshold and result in greater perceived exertion. There are a variety of theories regarding how massage can enhance performance in athletics. A faster recovery for athletes after injury is possible according to the physiologists. This theory also suggests that athletes could benefit from strengthening their shoulders and arms by stretching their superficial muscles. Another theory suggests that the muscles that are tighter and shorter in the lower body may help to shorten the time to recover for athletes who engage in vigorous activities during competition. A strong abdominal muscle core helps prevent cramps and spasms that athletes experience during intense exercise. In addition to stretching and strengthening of muscles, sports massage may also increase the flexibility of athletes. Stretching muscles can help them become more flexible and open to movement and training. However, as athletes continue to train the muscles will eventually get tighter and limit their motion. To ease discomfort in the muscles, athletes should do exercises to stretch muscles that are tight. This is where massage therapy plays a crucial role. Research has shown that during periods of intense exercise or high intensity the athletes experience a significant increase in the production of cortisol. This is a stress hormone that signals physical stress. Studies have proven that cortisol boosts muscle strength and endurance during low intensity exercise. In the study endurance performance was assessed prior to and after athletes completed 30 sprints. During sprints, muscle twitch activity was recorded and the results indicated an increase in muscle strength following the sprints. The muscle's glucosamine levels increased strength. Glycogen is a source of energy that is found in muscles after intense exercise. When the body of the athlete undergoes a period of intense physical exertion, it releases large amounts of glycogen in order to replenish the energy lost during the sprints. A study by researchers at the University of Northumbria in the UK demonstrated that performing short sprints before a bout of competitive cycling produced a significant increase in the amount of muscle glycogen. The results of these studies suggest that massage therapy for sports can be beneficial to athletes when they are exercising and after it. The studies were done on healthy, non-athletes. If you have any conditions that affect circulation , like kidney disease, diabetes, or high blood pressure, it's recommended to consult with your physician before starting any form of therapy.